Conventionally, slipping clutches are in use as brakes for rolls in paper feeding mechanisms in copying machines, typewriters, etc., or as steady brakes in spindle portions in textile machinery, or as steady brakes in winding machines in photo film developers, plastic film formers, etc. As shown in FIG. 5, such a slipping clutch 40 comprises a hub 41, a pusher plate 43 connected to the hub 41 by means of a key 42, a friction plate 44 made of high strength fiber secured to the plate 43, and a metallic driven plate 45 adapted to transmit torque in cooperation with the friction plate 44. A spring 46 and a nut 47 generate an urging force to cause frictional contact of the friction plate 44 and the driven plate 45. A sliding bearing 48 rotatably supports the driven plate 45 and receives thrust force. When a torque is transmitted from the pusher plate 43 on the driving side to the driven plate 45, the driven plate 45 is adapted to cause slippage so as to transmit a torque while slipping. The value of the torque at the time when the slippage is taking place is generally called "slipping" torque.
However, as use is continued, metallic and fibrous worn particles are generated on the slipping surfaces of the driven plate 45 and the friction plate 44, which tends to cause fluctuation of the slipping torque. Furthermore, since there must be a clearance between the plate 43 and the hub 40 so as to allow the axial movement of the plate 43 relative to the hub 40, the clearance tends to cause misalignment of the plate 43 and driven plate 45 due to manufacturing tolerances, vibration, etc. Thus, it has been difficult to obtain a relatively small and stable slipping torque.